Influence and progress of tea pigment research: A comprehensive analysis of application of bibliometrics.

Tea pigment, as a natural pigment component in tea, has attracted much attention because of its unique health benefits. In recent years, with the deepening of scientific research, the research on biological activity, extraction technology and application of tea pigment has made remarkable progress. Through systematic bibliometrics analysis, this paper comprehensively combs and evaluates the research status of tea pigment. The propose is to provide valuable reference for future research and application. In this paper, the chemical structure of tea pigment is firstly summarized, and then its diverse biological activities, such as antioxidant, anti-inflammatory and anti-tumor, are deeply discussed, especially its potential application in the treatment of cardiovascular diseases and diabetes. In addition, the application prospect of tea pigment in food coloring, textile dyeing and other industrial fields is also discussed in detail. Through the collection and arrangement of a large number of research literatures, this paper analyzes the development trend, research methods and main achievements of tea pigment research, and pays special attention to the dosage and effect of tea pigment in practical application. These analyses not only contribute to a more comprehensive understanding of the characteristics and functions of tea pigments, but also provide scientific basis for the further development and application of tea pigments.

A Temporal Association between Regression of Pachydrusen and Use of Proprotein Convertase Subtilisin Kexin 9 Inhibitor: A Case Report.

Introduction: We aim to report the clinical course of a patient with pachychoroidopathy who experienced regression of subfoveal drusen during cholesterol treatment using PCSK9 inhibitors. Case Presentation: A 62-year-old woman who was visually asymptomatic complained of recent visual loss in the left eye (OS). She was diagnosed with foveal pachydrusen (OS) that had remained stable for 10 years. Three months after starting cholesterol treatment with a PCSK9 inhibitor, the latest class of lipid-lowering medication, her vision improved in parallel with gradual regression of material deposited beneath the retinal pigment epithelium (RPE). Recurrence of drusen was observed after discontinuing the drug. Conclusions: Use of PCSK9 inhibitors may improve the retina's lipid homeostasis by increasing the number of RPE-LDL receptors and partly contribute to the improvement of ocular phenotypes associated with dysfunctional RPE in pachychoroidopathy.

Formation mechanism of blue pigment in boiled lotus rhizome discs: Insight into the chelation of polyphenols and iron.

Boiled lotus rhizome discs (BLRDs), as common processed products of lotus rhizome, have gained increasing attention from consumers and food manufacturers. However, the blue pigment formed during boiling affects its appearance and reduces the appetite of BLRDs. In this study, the effects of polyphenols and iron contents on blue pigment formation in BLRDs in different regions and months were investigated. Results revealed that blue variation was more serious in March and April of the second year in Wuhan, and polyphenols and iron contents in these two months were significantly higher than those in other months. Then, UPLC and UV-Vis analysis showed that polyphenols causing the formation of blue pigment in BLRDs were L-dopa, gallocatechin, catechin, epigallocatechin, chlorogenic acid and epicatechin, among which L-dopa (52.450 mg/100 g in fresh lotus rhizome (FLR)) and gallocatechin (36.210 mg/100 g in FLR) possessed the greatest effect. Moreover, the ESI-Q-TOF-MS analysis of L-dopa-iron chelate and gallocatechin-iron chelate suggested that the blue pigment of BLRDs was mainly in the form of bis-complexes under boiling conditions. The study on formation mechanism of blue pigment in BLRDs can provide a reference for lotus rhizome processing.

Activation of retinoid X receptors protects retinal neurons and pigment epithelial cells from BMAA-induced death.

Exposure to the non-protein amino acid cyanotoxin ß-N-methylamino-L-alanine (BMAA), released by cyanobacteria found in many water reservoirs has been associated with neurodegenerative diseases. We previously demonstrated that BMAA induced cell death in both retina photoreceptors (PHRs) and amacrine neurons by triggering different molecular pathways, as activation of NMDA receptors and formation of carbamate-adducts was only observed in amacrine cell death. We established that activation of Retinoid X Receptors (RXR) protects retinal cells, including retina pigment epithelial (RPE) cells from oxidative stress-induced apoptosis. We now investigated the mechanisms underlying BMAA toxicity in these cells and those involved in RXR protection. BMAA addition to rat retinal neurons during early development in vitro increased reactive oxygen species (ROS) generation and polyADP ribose polymers (PAR) formation, while pre-treatment with serine (Ser) before BMAA addition decreased PHR death. Notably, RXR activation with the HX630 agonist prevented BMAA-induced death in both neuronal types, reducing ROS generation, preserving mitochondrial potential, and decreasing TUNEL-positive cells and PAR formation. This suggests that BMAA promoted PHR death by substituting Ser in polypeptide chains and by inducing polyADP ribose polymerase activation. BMAA induced cell death in ARPE-19 cells, a human epithelial cell line; RXR activation prevented this death, decreasing ROS generation and caspase 3/7 activity. These findings suggest that RXR activation prevents BMAA harmful effects on retinal neurons and RPE cells, supporting this activation as a broad-spectrum strategy for treating retina degenerations.

Terahertz time-domain spectro-imaging and hyperspectral imagery to investigate a historical Longwy glazed ceramic.

In this paper, we present the potential of Terahertz Time-Domain Imaging (THz-TDI) as a tool to perform non-invasive 3D analysis of an ancient enamel plate manufactured by Longwy Company in France. The THz data collected in the reflection mode were processed using noise filtering procedures and an advanced imaging approach. The results validate the capability to identify glaze layers and the thickness of ceramic materials. To characterize the nature of the pigments, we also use with X-ray images, visible near-infrared hyperspectral imaging spectroscopy, and p-XRF (portable X-ray fluorescence) to qualitatively and quantitively identify the materials used. The obtained information enables a better understanding of the decoration chromogens nature and, thus, to determine the color palette of the artists who produced such decorative object. We also establish the efficiency of a focus, Z-tracker, which enables to perform THz imaging on non-flat samples and to attenuate artifacts obtained with a short focus lens. Then, 3D images are extracted and generated, providing a real vision. We also report the evaluation of the internal damage state through the detection of fractures.

Imaging macular carotenoids and their related proteins in the human retina with confocal resonance Raman and fluorescence microscopy.

Lutein and zeaxanthin are highly concentrated at the central region of the human retina, forming a distinct yellow spot known as the macula lutea. The delivery and retention of the macular pigment carotenoids in the macula lutea involves many proteins, but their exact roles remain incompletely understood. In our study, we examined the distribution of the twelve known macular carotenoid-related proteins within the human macula and the underlying retinal pigment epithelium (RPE) using both fluorescence and Raman modes on our confocal resonance Raman microscope. Additionally, we assessed protein and gene expression through Western blot analysis and a single-cell RNA sequencing database. Our findings revealed that GSTP1, BCO2, and Aster-B exhibited distribution patterns similar to the macular carotenoids, with higher expression levels within the macular region compared to the periphery, while SR-BI and ABCA1 did not exhibit specific distribution patterns within the macula or RPE. Interestingly, LIPC, SR-BI's partner, accumulated specifically in the sub-foveal RPE. All three of these carotenoid transport proteins were found to be highly expressed in the RPE. These results offer valuable insights into the roles these proteins play in the formation of the macula lutea.

Cerebral vasculitis presenting as acute posterior multifocal placoid pigment epitheliopathy in a 16-year-old male.

Purpose: To report on a case of the successful treatment of Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) in a pediatric patient with a prior diagnosis of cerebral vasculitis. Observations: A 16-year-old male with a prior diagnosis of cerebral vasculitis presented without ocular complaints. Visual acuity was 20/20, and color vision remained normal. Fundus examination revealed yellowish-white placoid lesions and retinal pigmented epithelial changes involving the posterior pole. A work-up including a rapid plasma reagin test, complete cell blood count, comprehensive metabolic panel, and urinalysis was within normal limits. A head computed tomography angiography without contrast and a brain magnetic resonance imaging scan were compatible with acute and past episodes of ischemia. Ancillary testing was compatible with an assessment APMPPE. Immunosuppressive and monoclonal antibody therapy resulted in the improvement and remission without residual neurologic deficits and with a BCVA of 20/20. Conclusionand Importance: This case suggests that a diagnosis of cerebral vasculitis should prompt physicians to consider an ophthalmic evaluation that includes a dilated fundus exam, regardless of the presence or absence of ocular symptoms. Ophthalmic findings may affect the diagnostic processes, particularly concerning infectious and non-infectious etiologies, or potentially neoplastic diseases.

Spatial phytoplankton community structure revealed by photosynthetic pigments in the tropical estuarine-coastal zone (Bangladesh).

To explore the variation of phytoplankton community along the Bakkhali river estuary and its adjacent coastal water in the north of the Bay of Bengal, total Chl-a (TChl-a) concentrations and group-specific photosynthetic pigments were investigated during April 2017. Distinct spatial distribution was observed in temperature, turbidity and nutrient concentrations as well as in TChl-a concentrations, showing a seaward decreasing pattern. The different distribution of phytoplankton pigments and functional groups along the gradients was also observed. Chlorophyll-b and zeaxanthin showed their highest abundance in the turbid riverine water, while alloxanthin and prasinoxanthin dominated in the coastal water. High concentrations of fucoxanthin, peridinin and hex-fucoxanthin were associated with high-light availability and showed a seaward increasing trend. Three phytoplankton groups can be classified: the riverine group (chlorophytes and cyanobacteria), the coastal group (cryptophytes and prasinophytes) and the offshore group (diatoms, dinoflagellate and haptophytes_type 6). The predominance of cryptophytes (avg. 48%) over diatoms (avg. 28%) was basically influenced by the scarcity of nitrogen and silicate relative to phosphate. Not only availability of nutrients, the photosynthetically active radiation also plays a key role in regulating TChl-a, photosynthetic pigments and functional groups in this tropical estuarine-coastal zone.

Dielectrophoretic characterization of peroxidized retinal pigment epithelial cells as a model of age-related macular degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is a prevalent ocular pathology affecting mostly the elderly population. AMD is characterized by a progressive retinal pigment epithelial (RPE) cell degeneration, mainly caused by an impaired antioxidative defense. One of the AMD therapeutic procedures involves injecting healthy RPE cells into the subretinal space, necessitating pure, healthy RPE cell suspensions. This study aims to electrically characterize RPE cells to demonstrate a possibility using simulations to separate healthy RPE cells from a mixture of healthy/oxidized cells by dielectrophoresis. METHODS: BPEI-1 rat RPE cells were exposed to hydrogen peroxide to create an in-vitro AMD cellular model. Cell viability was evaluated using various methods, including microscopic imaging, impedance-based real-time cell analysis, and the MTS assay. Healthy and oxidized cells were characterized by recording their dielectrophoretic spectra, and electric cell parameters (crossover frequency, membrane conductivity and permittivity, and cytoplasm conductivity) were computed. A COMSOL simulation was performed on a theoretical microfluidic-based dielectrophoretic separation chip using these parameters. RESULTS: Increasing the hydrogen peroxide concentration shifted the first crossover frequency toward lower values, and the cell membrane permittivity progressively increased. These changes were attributed to progressive membrane peroxidation, as they were diminished when measured on cells treated with the antioxidant N-acetylcysteine. The changes in the crossover frequency were sufficient for the efficient separation of healthy cells, as demonstrated by simulations. CONCLUSIONS: The study demonstrates that dielectrophoresis can be used to separate healthy RPE cells from oxidized ones based on their electrical properties. This method could be a viable approach for obtaining pure, healthy RPE cell suspensions for AMD therapeutic procedures.

Functionalized Collagen I Membranes as a Bruch's Membrane Mimetic for Outer Retinal In Vitro Models.

Physiologically relevant in vitro models of the human outer retina are required to better elucidate the complex interplay of retinal tissue layers and investigate their role in retinal degenerative disorders. Materials currently used to mimic the function of Bruch's membrane fail to replicate a range of important structural, mechanical, and biochemical properties. Here, we detail the fabrication of a surface-functionalized, fibrous collagen I membrane. We demonstrate its ability to better replicate a range of important material properties akin to the function of human Bruch's membrane when compared with a commonly utilized synthetic polyethylene terephthalate alternative. We further reveal the ability of this membrane to support the culture of the ARPE-19 cell line, as well as human pluripotent stem cell-derived RPE-like cells and human umbilical vein endothelial cells. This material could provide greater physiological relevance to the native Bruch's membrane than current synthetic materials and further improve the outcomes of in vitro outer retinal models.

Enhancing bioprocessing of red pigment from immobilized culture of gamma rays mutant of the endophytic fungus Monascus ruber SRZ112.

Considerable attention has been paid to exploring the biotechnological applications of several Monascus sp. for pigment production. In this study, our focus is on enhancing the bioprocessing of red pigment (RP) derived from the endophytic fungus Monascus ruber SRZ112. To achieve this, we developed a stable mutant strain with improved productivity through gamma irradiation. This mutant was then employed in the immobilization technique using various entrapment carriers. Subsequently, we optimized the culture medium for maximal RP production using the Response Surface Methodology. Finally, these immobilized cultures were successfully utilized for RP production using a semi-continuous mode of fermentation. After eight cycles of fermentation, the highest RP yield by immobilized mycelia reached 309.17 CV mL-1, a significant increase compared to the original titer. Importantly, this study marks the first report on the successful production of Monascus RP in a semi-continuous mode using gamma rays' mutant strain, offering prospects for commercial production.

Comparative omics directed gene discovery and rewiring for normal temperature-adaptive red pigment synthesis by polar psychrotrophic fungus Geomyces sp. WNF-15A.

The Antarctic fungus Geomyces sp. WNF-15A can produce high-quality red pigments (AGRP) with good prospects for the use in food and cosmetic area. However, efficient AGRP synthesis relies on low-temperature and thus limits its industrial development. Here genome sequencing and comparative analysis were performed on the wild-type versus to four mutants derived from natural mutagenesis and transposon insertion mutation. Eleven mutated genes were identified from 2309 SNPs and 256 Indels. A CRISPR-Cas9 gene-editing system was established for functional analysis of these genes. Deficiency of scaffold1.t692 and scaffold2.t704 with unknown functions highly improved AGRP synthesis at all tested temperatures. Of note, the two mutants produced comparable levels of AGRP at 20 °C to the wild-type at 14 °C. They also broke the normal-temperature limitation and effectively synthesized AGRP at 25 °C. Comparative metabolomic analysis revealed that deficiency of scaffold1.t692 improved AGRP synthesis by regulation of global metabolic pathways especially downregulation of the competitive pathways. Knockout of key genes responsible for the differential metabolites confirmed the metabolomic results. This study shows new clues for cold-adaptive regulatory mechanism of polar fungi. It also provides references for exploitation and utilization of psychrotrophic fungal resources.

Macular hole with retinal pigment epithelium tear after anti-VEGF therapy in an eye with neovascular age-related macular degeneration.

Purpose: To report a case of a full-thickness macular hole (FTMH) associated with a retinal pigment epithelium (RPE) tear after anti-vascular endothelial growth factor (anti-VEGF) therapy for neovascular age-related macular degeneration (nvAMD), which was successfully closed by vitreous surgery. Observations: A 73-year-old man with nvAMD in the right eye received an intravitreal aflibercept injection due to enlarged pigment epithelial detachment. However, 2 days after the third injection, the patient experienced a sudden decline in vision. An FTMH with a tear in the underlying RPE was detected. The FTMH was closed using vitrectomy combined with the inverted internal limiting membrane (ILM) flap technique. Conclusions and Importance: Our case highlights a rare complication of both an FTMH and an RPE tear after anti-VEGF therapy. Vitrectomy, with the inverted ILM flap technique, proved effective in closing the FTMH despite the complexity of the case.

Progression rate of macular retinal pigment epithelium atrophy in geographic atrophy and selected inherited retinal dystrophies. A systematic review and meta-analysis.

PURPOSE: To compare the macular retinal pigment epithelium (RPE) atrophy progression rate of selected degenerative and macular inherited retinal diseases (IRD). DESIGN: Systematic review and meta-analysis. METHODS: The protocol was registered on the PROSPERO database. Medline, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar were searched up to 15/Sep/2023 for articles reporting the RPE atrophy growth rate in treatment-naïve eyes with geographic atrophy (GA), Stargardt disease (STGD1), Best disease, pseudoxanthoma elasticum (PXE), central areolar choroidal dystrophy (CACD), or pattern dystrophies with no previous or current macular neovascularization and a minimum follow-up time of 12 months. Meta-analyses determined mean RPE atrophy growth rates per disease, imaging modality (fundus autofluorescence [FAF], optical coherence tomography [OCT], or color fundus photography [CFP]) and metric (mm2/year or mm/year). The Newcastle-Ottawa scale and the Cochrane Risk-of-Bias tool assessed the risk of bias, and funnel plots were used to evaluate small-study effects. RESULTS: From 4354 publications, 85 were included for meta-analysis: 69 studies (7815 eyes) on GA, 15 (1367 eyes) on STGD1, and one on both. Two studies on PXE were only eligible for review. No studies for other diseases met our eligibility criteria. The overall mean RPE atrophy growth rate for GA using FAF was 1.65 mm2/year (95% confidence interval [CI], 1.49-1.81) and 0.35 mm/year (95% CI, 0.28-0.41); using OCT, it was 1.46 mm2/year (95% CI, 1.28-1.64) and 0.34 mm/year (95% CI, 0.28-0.40); and on CFP it was 1.76 mm2/year (95% CI, 1.56-1.97) and 0.30 mm/year (95% CI, 0.28-0.31). For STGD1, using FAF it was 1.0 mm2/year (95% CI, 0.77-1.23) and 0.20 mm/year (95% CI, 0.17-0.23); on OCT, it was 0.80 mm2/year (95% CI, 0.72-0.88). No studies on STGD1 reported the growth rate with other imaging modalities or metrics. Growth rates in GA were faster than in STGD1 (p<0.05). A larger baseline area of atrophy was generally associated with faster growth rates. CONCLUSION: The RPE atrophy growth rate in GA is faster than in STGD1 but with great variation between studies and imaging modalities. Limited information was available for other macular IRD, suggesting further research is needed.

Predict and Protect: Evaluating the Double-Layer Sign in Age-Related Macular Degeneration.

INTRODUCTION: Advanced age-related macular degeneration (AMD) is a major cause of vision loss. Therefore, there is interest in precursor lesions that may predict or prevent the onset of advanced AMD. One such lesion is a shallow separation of the retinal pigment epithelium (RPE) and Bruch's membrane (BM), which is described by various terms, including double-layer sign (DLS). METHODS: In this article, we aim to examine and clarify the different terms referring to shallow separation of the RPE and BM. We also review current evidence on the outcomes associated with DLS: firstly, whether DLS is predictive of exudative neovascular AMD; and secondly, whether DLS has potential protective properties against geographic atrophy. RESULTS: The range of terms used to describe a shallow separation of the RPE and BM reflects that DLS can present with different characteristics. While vascularised DLS appears to protect against atrophy but can progress to exudation, non-vascularised DLS is associated with an increased risk of atrophy. Optical coherence tomography (OCT) angiography (OCTA) is the principal method for identifying and differentiating various forms of DLS. If OCTA is unavailable or not practically possible, simplified classification of DLS as thick or thin, using OCT, enables the likelihood of vascularisation to be approximated. Research is ongoing to automate DLS detection by applying deep-learning algorithms to OCT scans. CONCLUSIONS: The term DLS remains applicable for describing shallow separation of the RPE and BM. Detection and classification of this feature provides valuable information regarding the risk of progression to advanced AMD. However, the appearance of DLS and its value in predicting AMD progression can vary between patients. With further research, individualised risks can be confirmed to inform appropriate treatment.

Age-related macular degeneration (AMD) is an eye disease that may develop in older people, usually those aged over 60 years. Early in the disease, people often do not show any symptoms, but as the disease progresses, vision loss may occur. The advanced forms of AMD are called neovascular AMD (also called "wet" AMD) and advanced dry AMD (called geographic atrophy; GA). It is important to identify features and signs on eye scans that can help to predict if someone with AMD will develop an advanced form of the disease because this will help doctors plan the most appropriate treatment. One such feature on eye scans is the double-layer sign (DLS). In this article, we summarise the different names used for DLS, and assess if having a DLS increases the likelihood of someone with early AMD developing wet AMD or GA. We conclude that how DLS looks varies between people, which leads to DLS being called by various names. Someone with early AMD and a DLS containing blood vessels may be more likely to develop wet AMD; whereas someone with early AMD and a DLS without blood vessels may be more likely to develop GA. Taking photos of the eye using optical coherence tomography angiography imaging is the main method of identifying DLS and confirming whether it contains blood vessels.

Visual arsenic detection in environmental waters: Innovating with a naked-eye biosensor for universal application.

Arsenic contamination in environmental water sources poses a significant threat to human health, necessitating the development of sensitive and accessible detection methods. This study presents a multidimensional optimization of a bacterial biosensor for the susceptible and deoxyviolacein (DV)-based visual detection of arsenic. The research involved screening six different arsenic resistance (ars) operons and optimizing the genetic circuit to minimize background noise. Introducing an arsenic-specific transport channel enhanced the sensor's sensitivity to 1 nM with a quantitative range from 0.036 to 1.171 µM. The pigment-based biosensor offers a simple colorimetric approach for arsenic detection without complex instrumentation. The preferred biosensor demonstrated characteristics of anti-chelating agent interference, consistently quantified As(III) concentrations ranging from 0.036 to 1.171 µM covering the World Health Organization (WHO) drinking water limit. Innovatively, it effectively detects arsenic in seawater within a linear regression range of 0.071 to 1.125 µM. The biosensor's selectivity for arsenic was confirmed, with minimal cross-response to group 15 metals. Our naked-eye biosensor offers a novel approach for the rapid, on-site detection of arsenic in various water sources. Its simplicity, cost-effectiveness, and versatility make it a valuable tool for environmental monitoring and public health initiatives.

Response of the phytoplankton community to the cessation of wastewater discharges in the urdaibai estuary (SE bay of biscay) based on PIGMENTUM analysis of HPLC pigments.

Phytoplankton responds rapidly to nutrient availability variations, becoming a useful indicator for eutrophication and/or management actions to reduce it. The present study evaluated the medium-term response of the phytoplankton community of a temperate estuary (Urdaibai estuary) to the cessation of discharges from a wastewater treatment-plant (WWTP), comparing the physicochemical conditions and the phytoplankton community before (2020) and after (2022) the sewerage works. The cessation led to a decrease of ammonium and phosphate, causing decreases of phytoplankton biomass in the outer and middle estuary and increases in the surroundings of the WWTP. Community composition also changed, recording an increase of prasinoxanthin-containing algae's contribution to total biomass, and a composition shift in the inner estuary, from mainly flagellates (alloxanthin-containing and chlorophyll b-containing algae) to the increase of diatoms, which could be prompted by the change of nutrient-ratios and the nitrogen source, and might indicate the recuperation of the system.

Association of macular pigment optical density with plasma macular carotenoids levels and serum lipids in South Indian healthy volunteers and patients with early age-related macular degeneration.

Purpose: The objective of the present study was to investigate the relationship between macular pigment optical density (MPOD) and plasma carotenoids [(L) and (Z)] and serum lipids in South Indian young healthy volunteers and patients with early age-related macular degeneration (AMD). Methods: Two hundred and fourteen (N = 214) study participants (Healthy control group (N) = 178; Early AMD group (N) = 36) were enrolled after getting their written informed consent. The MPOD of the study participants was assessed using MPS II (Electron Technology, UK) after completing their routine ocular examination. Serum lipids were measured by the standard technique. Plasma levels of L, Z, lycopene and beta-carotene were estimated by high performance liquid chromatography with photo diode array detector. Statistical analysis used: Correlations among variables in serum, plasma and the MPOD were established using Spearman's rho correlation coefficient. Results: The overall mean MPOD in healthy control group and early AMD group were found to be 0.47 ± 0.16 (N = 178; 317 eyes) and 0.35 ± 0.22 (N = 36; 38 eyes) at 1° eccentricity respectively and were found to be statistically significant (p < 0.001). A strong positive association was found between plasma L, Z and L + Z and MPOD. Serum HDL showed a strong negative association with MPOD and other lipids showed a very weak association. MPOD was unaffected by body mass index. Conclusions: MPOD is positively associated with plasma L,Z and L + Z, adding further evidence that additional intake of L/Z may be beneficial in delaying the risk of AMD in our population.

Biocompatible melanin from the marine black yeast Hortaea werneckii R23 with antioxidant and photoprotection property.

Pigments from diverse sources have a great deal of interest due to its multifaceted applications. Hence, this study reports the physicochemical and functional characterization of the black pigment melanin from the marine black yeast Hortaea werneckii R23. In the present study, Hortaea werneckii R23, produced a black pigment in the yeast biomass. The pigment was extracted from the harvested yeast biomass and followed by pigment purification, characterization and identification was done. Physicochemical characterization of the pigment showed acid precipitation, alkali solubilization, insolubility in most organic solvents and water. The black pigment was confirmed as melanin based on ultraviolet-visible spectroscopy, Fourier-transform infrared, and Nuclear magnetic resonance spectroscopy analyses. Furthermore, the analyses of the elemental composition indicated that the pigment possessed a moderately high percentage of nitrogen and also detectable proportion of sulfur. All these Physicochemical properties indicated that H. werneckii melanin (HwM) mostly consisted of eumelanin. HwM exhibited strong antioxidant potential as reactive oxygen species (ROS) scavenger by in vitro DPPH (1,1-diphenyl-2-picryl hydrazyl) and ABTS (2,2-azinobis-3-ethyl-benzothiozoline-6-sulphonic acid) radical scavenging assay, and lipid peroxidation assay. The photoprotectant role of HwM on UV-irradiated human epithelial cells (HEp-2) revealed its potential effect in photoprotection. In addition, cytotoxicity study by XTT and SRB assay confirmed its biocompatibility with HEp-2 cells. From these findings, it is evident that the HwM from the marine black yeast possesses strong antioxidant and photoprotectant activity, moreover, it is biocompatible to human epithelial cells. So HwM could be used as a protective agent against oxidative stress associated disorders in an environment-friendly perspective.

Low-dose intravitreal injection of 4 mg preservative-free gentamicin and superficial lamellar keratectomy combined with modified Gundersen grafts to control chronic heterochromic iridocyclitis and secondary keratitis in horses.

OBJECTIVE: To describe a combined treatment approach for heterochromic iridocyclitis and secondary keratitis (HIK) in horses. ANIMAL STUDIED: A total of 15 horses (16 eyes). PROCEDURES: Sixteen eyes from 15 horses (mean age 14.1 years, range 6-26 years) received low-dose (4 mg) intravitreal preservative-free gentamicin injection (IVGI) and modified Gundersen grafts with standing sedation and local anesthesia following a clinical diagnosis of HIK. Additional therapies of suprachoroidal triamcinolone (8 mg) injection, episcleral bromfenac implants, and suprachoroidal cyclosporine implants were performed in individual cases. Leptospira titers were also reported when available. RESULTS: The most frequent ophthalmic findings were pigmented keratic precipitates (n = 15/16 eyes, 94%), corneal edema (n = 14/16 eyes, 88%), and pigmented cells suspended in the anterior chamber (n = 7/16 eyes, 44%). Postoperative treatment generally consisted of topical and systemic NSAIDs, topical antibiotics, and a topical mydriatic agent. Complications included persistent corneal edema (7/16, 44%), corneal ulceration (6/16, 38%), graft failure requiring revision (2/16, 13%), stromal abscess (1/16, 6%), surgery site infection (1/16, 6%), and suspected retinal degeneration following IVGI (1/16, 6%). One case was enucleated 6 months after treatment (1/16, 6%). Of the 12 eyes with at least 3 months of post-treatment follow-up, 10 were comfortable and visual with static or improved symptoms of HIK. CONCLUSIONS: This multimodal treatment approach aims to address both the anterior uveitis and endothelial decompensation frequently seen in horses with HIK. The surgery can be performed under standing sedation. Continued evaluation and long-term follow-up is necessary in all horses with HIK.